1. Field of the Invention
This invention relates to a front holder-incorporating connector having a front holder which prevents elastic retaining piece portions (which retain terminals on a housing) from being brought out of retaining engagement with the terminals.
The present application is based on Japanese Patent Application No. Hei. 9-244310, which is incorporated herein by reference.
2. Description of the Related Art
Generally, in a connector used in the wiring in a vehicle or the like, when terminals are mounted in a housing, elastic retaining piece portions are retainingly engaged respectively with the terminals inserted respectively into terminal receiving chambers in the housing. One example of such a connector is a front holder-incorporating connector in which a member (front holder) for preventing the flexing (elastic deformation) of the elastic retaining piece portions, retainingly engaged respectively with the terminals, is mounted on the housing, thereby retaining the terminals against withdrawal in a double manner.
For example, in a male-type front holder-incorporating connector in which male terminals are mounted in such a manner that contact portions (male tabs), formed respectively at front ends of these terminals, project in a connector fitting direction, and tab insertion holes, through which the male tabs project from the housing, are formed in a front (fitting side) end surface of the housing. Terminal receiving chambers for respectively receiving the male terminals are formed in the housing, and these terminal receiving chambers communicate respectively with the tab insertion holes. An elastic retaining piece portion is formed within each of the terminal receiving chambers, and is integrally connected at its proximal end to the housing, and its free distal end portion is movable into and out of the housing. More specifically, during the insertion of the male terminal into the terminal receiving chamber, the male terminal is brought into sliding contact with the elastic retaining piece portion, so that the elastic retaining piece portion is once flexed into a retraction space formed adjacent to the terminal receiving chamber, and after the male terminal is completely inserted into the terminal receiving chamber, the elastic retaining piece portion is elastically restored into the terminal receiving chamber to be retainingly engaged with a retaining portion of the male terminal, thereby retaining the male terminal in the terminal receiving chamber against withdrawal.
The above retraction spaces are open to the front end surface of the housing. A front holder can be removably attached to the front end surface of the housing. The front holder has projecting leg portions which can be inserted respectively into the retraction spaces.
In such a front holder-incorporating connector, the male terminals are mounted respectively in the terminal receiving chambers, and then the front holder is attached to the front end surface of the housing. As a result, the leg portions of the front holder are inserted respectively into the retraction spaces, thereby preventing the elastic retaining piece portions from moving into the respective retraction spaces, and therefore each of the elastic retaining piece portions is prevented from being brought out of retaining engagement with the associated male terminal, thus preventing the withdrawal of each terminal in a double manner.
In the above conventional front holder-incorporating connector, generally, the male tabs 7, projecting respectively through the tab insertion holes 5 formed in the front end surface 3 of the housing 1, respectively contact abutment surfaces 5a of the tab insertion holes 5 only at their upper surfaces, as shown in FIG. 8. Particularly where the width of the elastic retaining piece portion 9 is equal to the width of the male tab 7, it is difficult to provide upper and lower abutment surfaces of the tab insertion hole, which can contact the male tab 7, because of a mold-releasing operation effected when the housing is molded. On the other hand, in the conventional front holder-incorporating connector, an inner peripheral surface of each male tab insertion hole in the front holder 11 is kept out of contact with the male tab 7. Therefore, when the front holder 11 is attached to the housing, the male tab 7 contacts the abutment surface 5a only at its upper surface, and therefore is liable to move upward and downward, and for example, when a mating connector 13 is inserted into this connector, with the male tabs 7 inclined downwardly as shown in FIG. 8, the distal ends of the male tabs 7 are not aligned with insertion guide recesses 15 in the mating connector 13, and strike against a front end surface of the mating connector 13, which results in a possibility that the male tabs 7 are deformed or damaged.
As shown in FIG. 9, in the case where terminal receiving chambers 17 are arranged in a plurality of rows in a vertical direction, and leg portions 21 to be inserted respectively into retraction spaces 19 are provided in a vertically-asymmetrical manner, a front holder 11 can not be easily inserted in a parallel manner when attaching this front holder to the connector, and an angular moment in a direction of arrow a develops on that side of the front holder facing away from the leg portions 21, which invites a problem that the efficiency of the holder-attaching operation is much lowered. In contrast, if the front holder is formed into a vertically-symmetrical design only for this reason, the efficiency of the holder-attaching operation can be enhanced, but the front holder and the housing are increased in size.